This invention relates to improvements in precast structural panel construction and in the molds for forming precast panels, particularly molds of this type having the advantages of light weight and portability and rapid stripping and resetting, and which provide an improved forming system as compared to the mold construction shown and described in my U.S. Pat. No. 4,181,286, issued Jan. 1, 1980.
In precast concrete wall and floor construction and other building applications, waffle-shaped panels and slabs provide numerous advantages including a substantial saving in material, weight and money, as well as an architecturally advantageous three-dimensional configuration. In residential and commercial buildings the waffle design offers complete freedom to fully insulate exterior walls, modular window units may be inserted in the voided areas of the waffle without sacrificing wall strength, and electrical wiring and plumbing runs can be installed after the building structure is erected. Many interior load-bearing walls and ceilings need only to be painted or textured to give a pleasing and economical open beam effect. Since the skin in the voided areas is relatively thin (as compared to the structural webs or ribs of the waffle), these areas are readily penetrated with drills and saws to facilitate plumbing and mechanical and electrical work.
Furthermore, the waffle design lends itself to the use of modular precast structural units that can be formed either at an in-plant location or at the site itself. For on-site production, it is important that the molds be lightweight and portable and easily stripped and reset for rapid production. Durability, reusability and simplicity are also important since the conveniences of a plant facility and in-plant production machinery are not available. The reinforced plastic molds shown and described in the aforesaid U.S. Pat. No. 4,181,286 answered this need for lightweight, easy-to-operate molds that are particularly suited for on-site production. Although these molds have been used for years and have proven to be very satisfactory, the efficiency of forming systems of this type is enhanced when durability can be increased, simplicity of mold design is maximized, operation is improved, and the quality of the molded product is thereby enhanced.